Role of nanostructure on reaction and transport in Ni/Al intermolecular reactive composites
Date of this Version8-30-2012
Mathew J. Cherukara, Karthik Guda Vishnu, and Alejandro Strachan Phys. Rev. B 86, 075470. Vol. 86, Iss. 7
We use molecular dynamics to characterize the exothermic chemistry of Ni/Al nanolaminates for various temperatures, periodic lengths, and in the presence of extended defects. We show that the reaction is mass diffusion controlled for bulk nanolaminates, with the overall reaction time scaling with the square of the mean transport distance. The presence of voids or free surfaces not only leads to a significant decrease in reaction time (by as much as a factor of 5), but fundamentally changes the nature of the reaction. Free surfaces and voids running across several periods provide a mechanism for ballistic mass transport and change the scaling between reaction time and characteristic transport distance.
Nanoscience and Nanotechnology